Container and container-cap combination

ABSTRACT

A safety container and container cap combination, wherein the container may, for example, be a vial or a bottle, wherein a safety cap or stopper is permanently hinged to the top of one edge of the container. In one embodiment a slide channel extends diametrically through the cap or stopper, and a pair of recesses are positioned within the lip of the container on diametrically opposite sides thereof and in alignment with the slide channel to receive a pin member which may be retracted to disengage the recesses or, when the stopper is closed, extends through the slide channel into at least one of the said recesses firmly holding the stopper or cap in sealing engagement with the top of the container.

United States Patent 1191 1111 3,860,135 Yung et al. Jan. 14, 1975 [5CONTAINER AND CONTAINER-CAP 3,703,975 11/1972 Wittemer 215/213COMBINATION Inventors: Michael A. Yung, 4461 Cotton Ct.,

No. 4, Stockton, Calif. 95207; Bob Mar, 850 N. Baker St., Stockton,Calif. 95203 Filed: Jan. 23, 1974 Appl. No.: 435,675

Related U.S. Application Data Continuation-impart of Ser. No. 390,546,Aug. 22, 1973.

References Cited UNITED STATES PATENTS Turner 215/213 PrimaryExaminerGeorge T. Hall Attorney, Agent, or Firm-Ernest L. Brown [57]ABSTRACT A safety container and container cap combination, wherein thecontainer may, for example, be a vial or a bottle, wherein a safety capor stopper is permanently hinged to the top of one edge of thecontainer. In one embodiment a slide channel extends diametricallythrough the cap or stopper, and a pair of recesses are positioned withinthe lip of the container on diametrically opposite sides thereof and inalignment with the slide channel to receive a pin member which may beretracted to disengage the recesses or, when the stopper is closed,extends through the slide channel into at least one of the said recessesfirmly holding the stopper or cap in sealing engagement with the top ofthe container.

27 Claims, 20 Drawing Figures FATENTED JAN sum 10F 5 FIG. 3

PATENTED JAN 1 1915 FIG. l0

PATEHTED 1 H975 3,860,135

46 FIG. I?)

CONTAINER AND CONTAINER-CAP COMBINATION BACKGROUND OF THE INVENTION Thisapplication is a continuation-in-part of U.S. Pat. application Ser. No.390,546, filed Aug. 22, 1973 by Michael A. Yung and Bob Mar for aContainer and Container-Cap Combination.

This invention pertains to an improvement over the invention describedand claimed in U.S. Pat. application Ser. No. 358,008, filed May 7, 1963by John B. Lemons for a Container Cap.

Various states and foreign governments require or will require thatmedicine bottles and bottles containing poisons and other damagingfluids must have safety caps which may not be opened by immaturechildren. The caps are typically tested by placing them in the hands ofchildren below the age of 5 years to determine how many of such childrencan open the cap within a half-hour, an hour, 2 hours, etc.

The cap must, however, be readily openable by an adult, and it isexpected as the child matures he will also be able toopen the cap. It isfor'this reason that one might characterize the cap laws as childresistant cap laws rather than child-proof cap laws.

Very few other bottle caps can meet the government requirements. The capcontemplated by this invention,

however, has been thoroughly tested and is incapable of being opened bythe required number of immature children.

The container cap of the above-referenced patent application by John B.Lemons is a three part cap comprising a stopper seat which may bepermanently attached to the container or bottle, a stopper which may behinged to the stopper seat, for example, by a flexible hinge, and a pinmember which is positioned and adapted to slide in the stopper from onerecess on one side of the stopper seat, through a slide channel in thestopper, into a recess on the other diametrically opposed side of thestopper seat.

The pin and recesses, typically, have stops to prevent the pin fromfalling out of the stopper seat and to prevent the pin from being pushedin too far, whereby it could not conveniently be withdrawn. Typically atang is provided on the protruding end of the pin whereby one may graspthe tang with the finger nail to withdraw the pin from engagement withthe slide channel in the stopper, thereby allowing the stopper to beremoved from the stopper seat.

Other embodiments of the above-mentioned patent application utilize twoor more slide channels, positioned along chords of the stopper. Thechannels need not be precisely positioned; they need not be parallel;they need not be on the same plane; they need not be equi-distant fromthe center of the stopper.

It was also within the contemplation of the abovementioned patentapplication that two recesses be aligned within the stopper seat foreach slide channel in the stopper to receive a pin from that slidechannel. It was also contemplated that one of the recesses in each pairpenetrate the side of the stopper seat for withdrawal of the pin fromits respective slide channel. It was also contemplated that stops shouldbe provided for each pin and that each pin should have a finger-nailtang to enable its withdrawal.

BRIEF DESCRIPTION OF THE INVENTION The improvement of this invention isthat the pin always engages the slide channel on the stopper. Thestopper is provided with a slide channel for the pin, and the slidechannel has a shoulder-stop therein for engaging the correspondingshoulder on the pin to prevent full withdrawal of the pin from thestopper.

A second improvement is that the cap and bottle or other container arepreferably made in one piece. No stopper seat is required, and thestopper fits into the opening of the container. In a preferredembodiment the conforming bottle opening and stopper form a taperedseal. The stopper and container may be loosely attached to the bottle,or the stopper and container may be hinged tightly by a shorter strap sothat when the container is closed, one side of the stopper is heldtightly in place by the strap while the other side, or pouring side, ofthe stopper is held in place by the safety pin-member.

The lip of the container, in a preferred embodiment of this invention,has an inverted T opening for the sliding pin. When the pin is fullyengaged, a pair of ears extend in a circumferential direction to fitinto the circumferentially directed slots of the opening, preventing thepin and the stopper from being lifted. When the pin is withdrawn apredetermined distance, the narrower portion of the pin may be freelylifted through the notch forming the upper portion of the inverted T.

A tang for engagement of the pin by the fingernail is provided, and in apreferred embodiment the pin is slightly tapered from the tang endinwardly of the stopper.

It is therefore an object of this invention to provide a safety cap forcontainers.

It is also an object of this invention to provide a combined containerand safety cap for that container.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects will become apparentfrom the following description, taken in connection with theaccompanying drawings, in which:

FIG. 1 is a top view of a first embodiment of this invention with thestopper closed.

FIGS. 2a and 2b are sectional views taken at 2-2 in FIG. 1, showing thetwo extreme positions of the safety pin-member of this invention.

FIG. 3 is a sectional view taken at 3-3 in FIG. 1.

FIGS. 4a and 4b are side views of the embodiment of FIG. 1 in the closedand open positions.

FIG. 5 is a view taken from the left in FIG. 4a.

FIG. 6 is a view, partly in section, taken from the top in FIG. 4a.

FIG. 7 is a top view of a second embodiment of the invention.

FIG. 8 is a side view of the embodiment of FIG. 7.

FIG. 9 is an oblique view of one embodiment of the safety pin-member ofthe invention.

FIG. 10 is a sectional view of a third embodiment of the invention withthe cap closed and locked.

FIG. 11 is a view, partly in section and partly in profile of thethirdembodiment with the cap open.

FIG. 12 is a bottom oblique view of the locking pin shown in FIGS. 10and 11.

FIG. 13 is a sectional view of a fourth embodiment of the invention withthe cap closed but unlocked.

FIG. 14 is a top oblique view of the pin of the fourth embodiment.

FIG. 15 is a top view, partly in section, of a fifth embodiment of theinvention with the lock pin in its open unlocked position.

FIG. 16 is a top oblique view of the pin of the fifth embodiment.

FIG. 17 is a side view, partly in section, of the fifth embodiment ofthe invention.

FIG. 18 is a top view, partly in section, of the fifth embodiment of theinvention with the locking pin in its open position.

DETAILED DESCRIPTION OF THE INVENTION With increasing safetyconsciousness on the part of the public, various state legislatures andthe legislatures of foreign countries have passed laws requiring thatthe top of medicine bottles and bottles containing other harmfulmaterials must be resistant to the immature child. The measure of theadequacy of the resistance is how long it takes a child to open thebottle. The bottle top contemplated by this invention is extremelyresistant to opening by an immature child.

Referring to the drawings, this invention pertains to a container 10having a stopper 12, 12a, 12c, 12d attached, preferably, by a flexiblehinge member 14 to the container 10 or to a stopper seat 110. Thestopper 12, 12a, 12b, 12c, 12d fits into the mouth of the container 10or seat 110 to form a seal 16 or 16a.

Typically the stopper 12, 12b, 12c, 12d has a flange 18 or 18a whichextends over the lip 20 of the container 10 or seat 110. The lip 20 ofthe container 10 or seat 110 of the figures is overhung by the flange 18or 18a, the main difference between 18 and 180 being the amount ofoverhang. Flange 18 completely covers the lip 20 or 20a when the stopper12, 12a, 12b, 12c, 12d is closed to hide the safety pin-member 22, 22a,22b, 22c of this invention. The central portion 24 of the stopper 12,12a, 12b, 12c, 12d is typically depressed, as shown in the figures.Across one diagonal, not necessarily the diagonal in line with the hinge14, or the stopper 12, 12b, 12c, 12d is formed a slide channel 26, 26a,26b, 260. The slide channel 26, 26a, 26b, 26 c is typically positionedimmediately below the central portion 24 of the top of the stopper 12,12a, 12b, 12c, 12d. Note that the sealing portion, as at 16a in FIG. 3,may be conical rather than cylindrical as shown at 16.

The pin 22, 22a, 22b, 22c fits into the slide channel 26, 26a, 26b, 26c,respectively. The pin 22, 22a, 22b, 22c is preferably tapered from itsouter end 28 to its narrower inner end, although the taper wouldprobably be slight. The narrower inner end 30 may be short as shown inFIG. 9, or it may be longer to engage a recess 32 within the lip 20 ofthe container 10 or seat 110. Alternatively, the recess 32 may be agroove (not shown) within the inside of the lip 20 of the container 10or seat 110. When the end 30 is short as shown in FIG. 9, it does notextend into a detent in the lip 20, and it is preferable that the hinge14 be tightly adjusted to hold down that edge of the stopper 12, 12a,12b, 120 at all times.

In one embodiment (not shown), the recess 32 comprises an opening orwindow in the wall of the lip 20.

The pin 22 has a raised portion thereon with a shoulder stop 34 toengage a shoulder 36 within the slide channel 26. The side 38 of theraised portion 33 is beveled to avoid injuring the edge of the channel26a.

The pin 22a also has a raised portion 33a thereon with a shoulder stop34a to engage a shoulder 36a within the slide channel 26a. The side 38aof the raised portion 33a is beveled to avoid injuring the edges of theslide channel 26a when pin 22a is being inserted into the channel. Inthe embodiment of the pin 22a, the underside of the pin is under formedto a length beneath and extended beyond both sides of the raised portion33a, shoulder 34a and beveled side 38a to deflection of the pin when itis inserted into the channel 150. A slot 152 is formed in the undersideof most of the rest of the pin to minimize the shrinkage or warpage ofthe pin 22a during molding.

The slide channel 26 and 26a have a height sufficient to accomodate theraised portion 33, 33a in the region to the rightof the shoulder 36, 36ain FIGS. 2a, 2b, 10 and 11. In the region to the left of the shoulder36, 36a the height of the slide channel is only that needed for a loosefit (sliding fit) of the pin in the channel. Option ally the outside ofthe pin 22 may be roughened as shown at 40 to enhance the frictionbetween the side of the slide channel 26, 26a and the pin 22, 22a.

The pin 22b has a body which is substantially the same as the pin 22a.The pin 22b has a lowered portion 33b thereon with a shoulder stop 34bto engage a shoulder 36b on the bottom of the slide channel 26b. Theside 38b of the lowered portion 33b is beveled to avoid injury to thechannel 26a. In the embodiment of the pin 22b, the upper side of the pinis formed down along a length overlying the lowered portion 33b, side38b and shoulder 34b to allow deflection of the pin when it is inserted.A slot 152a is formed in the top side of most of the rest of the pin tominimize the shrinkage or warpage of the pin 22b during molding.

The pin 22c of FIGS. 15-17 has a pair of outwardly extending portions160, 162 positioned thereon with shoulder stops 164, 166 to engagecorresponding shoulders 168, 170 on the sides of the slide channel 260.The sides 172, 174 are beveled to avoid injury to the channel 26c. Aslot is formed into the center part of the pin 220, the slot extendingfrom the top to bottom of the pin 220 for approximately one-half of itslength, as at 182. The slot 180 is formed only a portion of the waythrough the thickness of the pin 22c, either on the top of the pin orthe bottom of the pin as shown at 184.

The outer end 28 of the pin 22, 22a, 22b, 22c has a pair of sidewardlyextending portions 42, 44 and an upwardly extending tang which may beengaged by the finger nail of the user. The tang 46 and the extendingportions 42, 44 fit into a matching window 50, as shown moreparticularly in FIG. 5, in the lip 20 of the container 10. The lip 20,as shown at 52 in FIG. 6, has an opening therein which is wide enough toallow the main portion 54 to be lifted therethrough, but the opening 53is not wide enough to allow the wings 42, 44 to be lifted therethrough.

In operation, the opened cap or stopper is shown in the position of FIG.4b. The pin 22, 22a, 22b, 22c is in its extended position. To close thecap, the cap is lowered into the mouth of the bottle 10 or stopper seat110, seating upon the seal 16 or 16a, the main portion 54 of the pin 22passing through the slot 53. The pin 22, 22a. 22b. 22c is then pushedinward until the two wings 42, 44 fit into the window 50. Preferably thepin 22, 22a, 22b, 22c is pushed inward until the end is flush with thesurface of the container 10. The end 30 of the pin 22, 22a, 22b, 22cengages the detent 32 (if that design is used). The cap is now locked.In the embodiment of FIGS. 1-6, the tang 46 is at least partly hid bythe overhanging flange 18. The spacing may vary from design to design,and the spacing may, if desired, be so small that a tool would be neededto grasp the tang 46 for opening.

To open the cap or stopper 12 or 12a, the tang 46 is grasped by thefinger nail or by a tool, pulling the pin 22 outward until the laterallyextending portions 42, 44 no longer engage the window 50 and the end 30no longer engages the recess or detent 32. Typically the shoulder 34 isagainst the shoulder 36, the shoulder 34a or 36b is against the shoulder36a or 36b, or the shoulders 164, 166 are against the shoulders 168, 170to prevent the pin 22 from being withdrawn from the stopper 12 or 12a.The stopper 12 or 12a is then lifted, the portion 54 of the pin 22sliding upward with the stopper through the slot 53.

In alternative embodiments of the invention, multiple pins such as 22,22a, 22b, 22d may be used in a plurality of slides such as 26, 26a, 26b,26c. The slides 26, 26a, 26b, 26c are typically upon chords of thestopper with corresponding detents or recesses such as 32 within the lipand openings such as window 50 and slot 53 for each pin.

The pin 22, 22a, 22b, 22c and slide channel 26, 26a, 26b, 26c is shownaligned with the hinge 14. Actually, it would frequently be preferableto have the pin 22 and slide channel 26 at some angle to the hinge 14.For example, the pin 22 and slide channel 26 could be at right anglesfrom its present position.

It may also be desirable to configure the window 50 as a pouring spout(not shown). The wings 42, 44 would then fit with the spout.

The embodiments of FIGS. 10, ll, l3, l5 utilize a stopper seat 110 whichis adapted to be attached to the top of a container.

In the embodiments of FIGS. l-9, l7, 18 the cap or stopper seatsdirectly into the mouth of container 10.

Initial alignment of the channel 26c with the detent 32 is facilitatedby the spacers 200, 202, 204 which are preferably downstanding from theflange 12, 12a, 12b, 12c, 12d of stopper, or they may be upstanding fromthe lip 20. The collar 18 sits on the spacers 200, 202, 204 are showncircumferentially positioned 120 apart, but other spacing and numbers ofspacers is within the contemplation of this invention. For example, thespacer could be a continuous collar (not shown).

The apparatus of this invention is a significant improvement in thefield of safety caps for medicine bottles and vials. As such, it isbelieved to have significant commercial appeal.

The safety cap or stopper of this invention is simple to open by amature person but very difficult and almost impossible for an immaturechild to open. The parts are relatively simple to manufacture andassemble.

Although the invention has been described in detail above, it is notintended that the invention should be limited by that description, butonly in accordance with the spirit and scope of that specificationtogether with the appended claims.

We claim:

1. In combination:

a container having an opening with a lip for filling and emptying saidcontainer;

a stopper, sized to fit into and substantially conform to said openingand said lip, including at least one slide channel formed in anddirected across said stopper;

at least one pin, equal in number to and positioned in said slidechannels;

at least one window and slot, equal in number to the 'number of saidslide channels, in the lip of said opening, and each aligned with oneend of a different one of said slide channels;

said slots being sufficiently large that said pin can be lifted throughsaid slot;

each said pin having an enlarged portion on one end thereof sufficientlysmall to fit within said windows and sufficiently large that saidenlarged portion cannot be lifted through said slot.

2. The combination of claim 1 in which each said pin has at least oneslot formed at least a part of the length of said pins to facilitateinsertion of said pins into said slide channels.

3. The combination of claim 1 in which each said pin has a portion ofits length reduced in thickness.

4. The combination of claim 1 and further comprismg:

at least one recess, equal in number to said slide channels, positionedand aligned with said channels on the end thereof, within said lip,opposite said windows and slots.

5. The combination of claim 4 in which said recesses comprise windows insaid lip.

6. The combination of claim 1 and further comprismg:

at least one recess positioned and aligned with a different one of saidslide channels on the end thereof, within said lip, opposite saidwindows and slots.

7. The combination of claim 6 in which said recesses comprise windows insaid lip.

8. The combination of claim 1 in which said window and slot arecontoured to have the circumferential dimension of said window greaterthan the width of said slot, said slot extending from said windowthrough said lip of said opening; said enlarged portions of said pinsbeing contoured to have a wider dimension than the main body of saidpins but no greater than the dimension of said window; said slots beingcontoured to have a width greater than the width of said main body ofsaid pins.

9. The combination of claim 8 and further comprising finger nail tangsupstanding from said enlarged portrons.

10. The combination of claim 1 in which said slide channel and said pinare positioned substantially upon a diameter of said stopper.

11. The combination of claim 9 in which said pin is tapered from a widerdimension from the end of said pin adjacent said enlarged portion to asmaller dimension on the distal end of said pin.

12. The combination of claim 11 in which each said pin has at least oneslot formed at least a part of the length of said pins to facilitateinsertion of said pins into said slide channels.

13. The combination of claim 11 in which each said pin has a portion ofits length reduced in thickness.

l4. The combination of claim 11 in which said enlarged portion of saidpin conforms substantially to said window with the edges thereofsubstantial radially directed relative to said container and the end ofsaid enlarged portion being contoured substantially to conform to theouter surface of said container when said pin is substantially fullyengaged.

15. The combination of claim 14 and further comprising:

at least one pin stop on said pin and at least one channel stop in saidchannel to engage said pin stop to limit disengaging travel of said pin.

16. The combination of claim 15 in which said pin stop is a shoulder ontop of said pin and .said channel stop is a shoulder on the top of saidchannel and facing said pin stop.

17. The combination of claim 15 in which said pin stop is a shoulder onthe bottom of said pin and said channel stop is a shoulder on the bottomof said channel facing said pin stop.

18. The combination of claim 15 in which said pin stop comprises atleast one shoulder on the side of said pin and said channel stopcomprises at least one shoulder on the corresponding side of saidchannel facing said pin stop.

19. The combination of claim 18 in which said pin has pin stops on bothsides thereof and said channel has channel stops on both sides thereoffacing said pin stops.

20. The combination of claim 1 and further comprisat least oneupstanding spacers positioned upon said lip, and a flange upon saidstopper, said flange being sized and positioned to rest upon saidspacers when said container is closed by said stopper.

21. The combination of claim 1 and further comprisa flange upon saidstopper, and at least one spacer depending from said lip, said spacersbeing sized and positioned to rest upon said lip when said container isclosed by said stopper.

22. The combination of claim 1 in which said enlarged portion of saidpin conforms substantially to said window with the edges thereofsubstantial radially directed relative to said container and the end ofsaid enlarged portion being contoured substantially to conform to theouter surface of said container when said pin is substantially fullyengaged.

23. The combination of claim 1 and further comprisat least one pin stopon said pin and at least one channel stop in said channel to engage saidpin stop to limit disengaging travel of said pin.

24. The combination of claim 23 in which said pin stop is a shoulder ontop of said pin and said channel stop is a shoulder on the top of saidchannel and facing said pin stop.

25. The combination of claim 23 in which said pin stop is a shoulder onthe bottom of said pin and said channel stop is a shoulder on the bottomof said channel facing said pin stop.

26. The combination of claim 23 in which said pin stop comprises atleast one shoulder on the side of said pin and said channel stopcomprises at least one shoulder on the corresponding side of saidchannel facing said pin stop.

27. The combination of claim 26 in which said pin has pin stops on bothsides thereof and said channel has channel stops on both sides thereoffacing said pin stops.

1. In combination: a container having an opening with a lip for fillingand emptying said container; a stopper, sized to fit into andsubstantially conform to said opening and said lip, including at leastone slide channel formed in and directed across said stopper; at leastone pin, equal in number to and positioned in said slide channels; atleast one window and slot, equal in number to the number of said slidechannels, in the lip of said opening, and each aligned with one end of adifferent one of said slide channels; said slots being sufficientlylarge that said pin can be lifted through said slot; each said pinhaving an enlarged portion on one end thereof sufficiently small to fitwithin said windows and sufficiently large that said enlarged portioncannot be lifted through said slot.
 2. The combination of claim 1 inwhich each said pin has at least one slot formed at least a part of thelength of said pins to facilitate insertion of said pins into said slidechannels.
 3. The combination of claim 1 in which each said pin has aportion of its length reduced in thickness.
 4. The combination of claim1 and further comprising: at least one recess, equal in number to saidslide channels, positioned and aligned with said channels on the endthereof, within said lip, opposite said windows and slots.
 5. Thecombination of claiM 4 in which said recesses comprise windows in saidlip.
 6. The combination of claim 1 and further comprising: at least onerecess positioned and aligned with a different one of said slidechannels on the end thereof, within said lip, opposite said windows andslots.
 7. The combination of claim 6 in which said recesses comprisewindows in said lip.
 8. The combination of claim 1 in which said windowand slot are contoured to have the circumferential dimension of saidwindow greater than the width of said slot, said slot extending fromsaid window through said lip of said opening; said enlarged portions ofsaid pins being contoured to have a wider dimension than the main bodyof said pins but no greater than the dimension of said window; saidslots being contoured to have a width greater than the width of saidmain body of said pins.
 9. The combination of claim 8 and furthercomprising finger nail tangs upstanding from said enlarged portions. 10.The combination of claim 1 in which said slide channel and said pin arepositioned substantially upon a diameter of said stopper.
 11. Thecombination of claim 9 in which said pin is tapered from a widerdimension from the end of said pin adjacent said enlarged portion to asmaller dimension on the distal end of said pin.
 12. The combination ofclaim 11 in which each said pin has at least one slot formed at least apart of the length of said pins to facilitate insertion of said pinsinto said slide channels.
 13. The combination of claim 11 in which eachsaid pin has a portion of its length reduced in thickness.
 14. Thecombination of claim 11 in which said enlarged portion of said pinconforms substantially to said window with the edges thereof substantialradially directed relative to said container and the end of saidenlarged portion being contoured substantially to conform to the outersurface of said container when said pin is substantially fully engaged.15. The combination of claim 14 and further comprising: at least one pinstop on said pin and at least one channel stop in said channel to engagesaid pin stop to limit disengaging travel of said pin.
 16. Thecombination of claim 15 in which said pin stop is a shoulder on top ofsaid pin and said channel stop is a shoulder on the top of said channeland facing said pin stop.
 17. The combination of claim 15 in which saidpin stop is a shoulder on the bottom of said pin and said channel stopis a shoulder on the bottom of said channel facing said pin stop. 18.The combination of claim 15 in which said pin stop comprises at leastone shoulder on the side of said pin and said channel stop comprises atleast one shoulder on the corresponding side of said channel facing saidpin stop.
 19. The combination of claim 18 in which said pin has pinstops on both sides thereof and said channel has channel stops on bothsides thereof facing said pin stops.
 20. The combination of claim 1 andfurther comprising: at least one upstanding spacers positioned upon saidlip, and a flange upon said stopper, said flange being sized andpositioned to rest upon said spacers when said container is closed bysaid stopper.
 21. The combination of claim 1 and further comprising: aflange upon said stopper, and at least one spacer depending from saidlip, said spacers being sized and positioned to rest upon said lip whensaid container is closed by said stopper.
 22. The combination of claim 1in which said enlarged portion of said pin conforms substantially tosaid window with the edges thereof substantial radially directedrelative to said container and the end of said enlarged portion beingcontoured substantially to conform to the outer surface of saidcontainer when said pin is substantially fully engaged.
 23. Thecombination of claim 1 and further comprising: at least one pin stop onsaid pin and at least one channel stop in said channel to engage saidpin stop to limit disengaging travel of said pin.
 24. The combination ofclAim 23 in which said pin stop is a shoulder on top of said pin andsaid channel stop is a shoulder on the top of said channel and facingsaid pin stop.
 25. The combination of claim 23 in which said pin stop isa shoulder on the bottom of said pin and said channel stop is a shoulderon the bottom of said channel facing said pin stop.
 26. The combinationof claim 23 in which said pin stop comprises at least one shoulder onthe side of said pin and said channel stop comprises at least oneshoulder on the corresponding side of said channel facing said pin stop.27. The combination of claim 26 in which said pin has pin stops on bothsides thereof and said channel has channel stops on both sides thereoffacing said pin stops.